These were the speakers to have in a nightclub or "Disco" back in the day and I'd bet they'd still sound good today.
Regardless of marketing hype, what sounded good back then would still sound good today.
The biggest issues with these speakers is the size and shape. Placing them in a room can be difficult.
If you don't want to re-foam you can buy replacement drivers from Parts Express. They're about $21.00 each (21 x 16 = $336)
https://www.parts-express.com/grs-rsb901-1-replacement-speaker-driver-for-bose-901-4-1-2-1-ohm--290-922